


Bonding

by InvisibleLee



Series: Undertale Shorts [2]
Category: Undertale (Video Game)
Genre: Bonding, Cute, F/M, Fluff, Short, Soriel, Sweet, simple
Language: English
Status: Completed
Published: 2017-04-13
Updated: 2017-04-13
Packaged: 2018-10-18 12:32:44
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,754
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10617003
Author URL: https://archiveofourown.org/users/InvisibleLee/pseuds/InvisibleLee
Summary: Sans watches Frisk for a day.





	

Sans and Toriel were of the punny type. It was pretty unsurprising, after their first official meeting. They had automatically shared in their pun interests, and had found they had conversed many times before. To both of them, it was like they had found a missing piece, a friend they had lost, and, better yet, they would be going to the Surface together, with Frisk and their other friends.

Upon arriving on the Surface, it was quickly noted that, after the arrival of Monsters was calmed by Frisk, they would need to stick together, the Monsters. After a few months, Toriel secured a rather large living arrangement for herself, Frisk, Flowey, Sans, and Papyrus. Most of the other Monsters had grouped up as they desire and were scattered across the Surface as they were slowly accepted into society.

The friendship solidified quickly between the Goat and Skeleton. Sans (and Papyrus) had taken on an Uncle-like role for Frisk, although it was, for Sans, very nearly a fatherly role - many times had Frisk caught themselves thinking of Sans as their father, as they did Toriel as their mother, simply because he was always there for them. There had been a few times they had nearly called them "Dad", as well, a slip up easy to make when so used to calling Toriel "Mom". In any case, Sans had certainly exceeded expectations as a partial caretaker. Toriel had become a teacher, of course, teaching Monster History in school, Papyrus had become a chef (of sorts) in a small restaurant, and - though he did not live with them, he did have the tendency to watch over Frisk - Asgore gardened at the school and around the neighborhood. This left Sans to watch Frisk when they weren't at school, as Toriel often was busy grading and such, the others equally busy with other necessary tasks.

Sans, at first, worried that it would be difficult, that he would mess it up. What if Frisk fell down the stairs, or off the swing in the backyard, or out of a tree, or- oh, stars- the balcony? However, watching the young child, especially as they grew older, proved to be very easy; they were often more than content to just watch television with him, having the tendency to snuggle close to him, as if stuffing themselves in his jacket, smiling happily. Some nights they would have to ask for help on homework - thankfully in the Math or Science areas, which Sans excelled at. Even though he tended to pretend he didn't get it, this made it so that Frisk learned on their own. There had been few times when anything bad had happened, and even when Frisk got hurt or something alike, there was never any issue from it, always set right with comforting words.

Sans had only ever watched Frisk for a few hours at a time, though, so when Toriel announced she would be leaving for the weekend, Sans' soul gave a flip of anxiety. His unwavering grin revealed nothing as he reassured her that Frisk would be in good _S-ands_ , which caused the monster to laugh, comforted. He waved goodbye to her as she drove away.

Stars. What was he supposed to do?

He remained on the porch, mulling over the situation. He had never had to watch Frisk for nearly this long. Papyrus was staying with Undyne and Alphys for the weekend, as well, so it was just himself and Frisk, as he didn't really count the potted plant monster - all he did was sleep and insult Sans when Frisk wasn't in earshot. He let out a sigh; he promised Tori he'd do this, so do it he would.

It was so easy.

The child, now almost twelve, was happy to do just about anything. For the rest of that first day, they watched television, and, despite Tori's usual restriction on eating out, Sans took Frisk out to Grillby's dive in-town. Frisk, giggling, had promised not to tell. When they returned after dinner, it was a simple task getting them ready for bed.

Getting Frisk _into_ bed, though. That was another story.

In fact, as Sans watched Frisk imitate a rock on the couch, he realised he had never seen Tori put the kid to bed; he was usually in bed himself by that point, or out with Papyrus doing something, or, well, not there. Now he realised that this wasn't very good; he had no clue how to get them to bed, without using his being cross or forcing them with his magic, neither of which Tori would approve of, he was sure.

"c'mon, kid, it's bed time. aren't you tired?"

Frisk shook their head curtly.

"frisk, c'mon. i'll read to ya."

Another shake.

"i'll make ya breakfast in the morning?"

"Uh-uh!" Now Frisk was voicing their displeasure, making Sans more frustrated.

"frisk, i'm being serious."

"So am- whoa!" Suddenly, Frisk was engulfed in a blue glow, something familiar, sending a shiver of fear through them. "S-Sans, p-put me d-down!" Sans had one hand outstretched from his pocket, levitating the child up above the couch by a small amount. Sans was startled to realise that he had done this so quickly, and even more startled to realise that it had clearly scared Frisk. He set them down quickly, concern softening his features, but once his magic dissipated, Frisk darted from the room.

Sans heard their door shut loudly, and the flower, resting in his pot on the end table, snorted.

"Way to go, numb-skull," Flowey insulted, "Do you even realise what-" He yelped as a small bone was tossed in his direction.

"shut up..." The skeleton gave a sigh and moved to stand outside of Frisk's door. He rapped on it gently. "kid...you okay in there?" No response. "frisk?" For a long moment, Sans wondered if he'd have use his magic to unlock the door, but when he pushed on it, it moved forward easily, if only because Frisk was opening it. It moved maybe two inches.

"I...I'm fine," Frisk said in a tiny voice, clearly not fine. "You just...startled me. I overreacted. Sorry." Usually, Sans would play along with Frisk's lies - this was not the first time something about Sans had spooked them. But he could not.

"look, kid, don't be. i should'nt'a done that, and-"

"Let's just forget it, Sans," Frisk interrupted, and they sounded different - Sans was struck by the thought that Frisk had been through more than he could know.

"so...uh...you're not tellin' Tori?" Sans said this with slight worry in his tone, and, suddenly, the door was wide open. It was clear Frisk had been crying in the short time that had passed, but now there was no evidence of sadness, only an intense curiosity.

"Is that what you were worried about?" Sans was a little relieved; it seemed as if this fact had derailed Frisk's fear.

"maybe," Sans replied, looking to the left. Out of the corner of his eye, he saw Frisk grin. "what's with the grin, kid?"

"You like Tori!" Frisk said in a singsong voice, smiling widely. Much to Sans' confusion, a cold blue blush spread over his face - skeletons didn't blush, what was this? He felt his soul give a powerful thump. Frisk laughed as they watched Sans struggle to calm himself. "See! You _like_ her!" Sans didn't respond, but Frisk didn't seem to notice. They drew themselves up.

"How about this. I'll help you ask her out."

Sans stared at Frisk for a long moment before stuttering, "b-but kid, I-"

"On the condition that you never, _ever_ use your magic on me like that again." Frisk's eyes were downcast, and Sans thought they might be close to crying again. "Otherwise...I tell Tori, and..." The sentence trailed, but Sans understood.

"deal."

-

The two started the next morning - they only had one day before Toriel returned, after all. The first step to Frisk's plan was to try to convert Sans from awkward to smooth.

"You can't stutter every time she asks you something," Frisk criticised. "Pretend I'm her." Frisk sat down on the couch, smiling gently at Sans in a good impression of one of Toriel's softer expressions. Sans tried to imagine the small child as the other Monster.

"h-hey, Tori-" Sans stopped himself. "kid, you're not her, i can't just-"

"Sans, you can talk to me, really," Frisk said, and it sounded so genuinely close to the inflection of Toriel that Sans started. Frisk giggled at this reaction, changing their voice back. "Just pretend, 'kay?" Sans gave a short nod, though now he closed his eyes - how he did this, Frisk would never know.

So the lesson began.

"Okay, now greet me," came Toriel's tones from Frisk. Sans took a breath.

"hey, tori." Thankfully, despite what Frisk had teased, his voice didn't waver, though that may have had more to do with the fact it wasn't _actually_ Toriel than that Sans had already made progress.

"Hello, Sans," came the voice again. "How are you?"

"feeling pretty _san-sational_ , myself. and you?" Frisk let out a laugh that sounded so much like Toriel's that Sans wondered if they didn't just have her voice tape recorded.

"That's a good one, Sans. How about this - knock knock?" Sans' grin grew wider.

"who's there?"

"Bone."

"bone who?"

"Bone m-"

"f-frisk!"

"Haha, I'm just joking! Maybe. A little. Or not. Besides, I was gonna say 'mom' not 'me'. Although, that honestly sounds just as bad...if not worse, wow. I'm pretty good."

"frisk, please..."

"Alright, alright, fine. Not too shabby for lesson one. But this is just practice. Next part. Dress to impress!"

Sans suddenly regretted everything. Frisk made him take them to the newly-made MTT Mall - Mettaton really had made an impression above ground - to go on a clothes search. Sans was then subjected to more than a couple hours of playing dress-up. Leather pants, cotton shirts, long sleeves, new sneakers, pressed pants, fancy watches...the range seemed endless. Finally, Sans walked out of the dressing room, wearing a dark, long sleeved shirt that contrasted against the white of his bones. He wore a pair of khaki shorts - the pants were too long, and shorts reached his ankles anyway - and shiny shoes that Sans was sure costed more than most of his own wardrobe at home. But Frisk grinned in delight.

"You look so _handsome!_ " Frisk squealed happily. " Mom is gonna _love_ it." Sans turned to look in the mirror nervously, tugging a little at the collar.

"i dunno, frisk...it's not really...me, y'know?" Frisk shook their head.

"That's not the point!" they said. "Come on, let's check out." Frisk tugged Sans to the cashiers, who, unsurprisingly, turned out to be Bratty and Catty.

"Frisk!" the two said in delight. Frisk replied with a smile.

"Sans wants to wear this out, okay? Ring us up?"

"Of course- oh, Sans, you look _hot_!" Bratty noted.

"Definitely!" Catty agreed. Sans looked away as the two scanned his various tags.

"That'll be two-fifty," Catty said. Sans felt his eyes widen. "Oh, but then apply manager discount, friend discount, the sale, and membership discount, so that'll be...ah-ha. Seventy, please. Sans blinked at the dramatic fall in price as Frisk passed over a hundred dollar bill.

"where...where did you even get that money, kid?"

"Paps. Remember my birthday last month?" Sans nodded. "Yeah, well, he forgot, sort of. So he gave me that." Frisk giggled. "He was so sincere, I couldn't tell him it didn't matter." They took the change from Bratty and left with a smile after Catty cut off all the tags. "So, how does it feel to be all dressed up?" Sans gave a grimace somehow, despite his permanent grin.

"it's really uncomfortable," he said. "you sure this will work, kid?" Frisk smiled widely, almost mischievous in nature.

"Of course!" Sans was uncertain for half of a second before relaxing; the kid hadn't lied to him since he'd known them, minus that time for his birthday, but that didn't really count.

At least, he didn't _think_ they'd lied.

Frisk was interrupting his thoughts, saying next, "Now that you're all dressed up, we've gotta get you up to speed with romance." Sans hitched up an eye...bone? Sure.

"really?"

"Yup! Some good old movies should help," Frisk replied, then laughed at his expression. "Not anime, I promise. Real movies. Like...Romeo and Juliet, minus all the death."

"...death?"

"It was kind of a tragic love story," Frisk replied. "Anyway, come on!"

Upon returning home, the two binge watched movies like _50 First Dates_ , which Sans watched rather intently, seeming to be actually interested, although Frisk didn't pay much attention themselves. After a marathon, the two then moved on to trying out pick-up lines that Frisk was sure would work.

"Okay, okay, try this one." Frisk slid the slip of paper over to him. He read it off.

"i love you with all my circle, but not my heart, because hearts break but circles go on forever." He gave a groan. "kid, this is awful." Frisk huffed.

"Do _you_ have anything better?" Suddenly, Sans was pulling out a piece of paper, sketching something, briefly glancing up to meet Frisk's gaze as he did. Finally he stopped.

"there." He showed it to Frisk. Frisk raised an eyebrow.

"Are those my eyes?"

"yup. it's a map, cause i keep getting lost in them." For a moment, Frisk was silent, before they laughed.

"Wow, maybe you _don't_ need help here. Mom's too into those jokes for them not to work." Sans grinned wider.

"so. am i ready, then?" Frisk smiled.

"I think so. Just make sure you wear what we bought and practice what you know. You'll do perfect." Sans nodded, suddenly serious.

"thank you, frisk. dunno what i'd do without ya, kid," he said sincerely. Then- "now, off to bed."

"Nope."

And there it happened again- Frisk refused to move, no matter how much Sans tried to barter. This time, though, he was extra careful to avoid using magic.

"do you want me to read to you?" Sans asked desperately. "or tuck you in or something?" For a moment, it seemed all of his efforts were futile, but then Frisk raised their arms to him as they often had to Toriel when they were years younger.

"Yeah." Sans let out a chuckle, picking up the child carefully and bringing them to their room. "You don't have to read," they said quickly. Sans smiled gently as he tucked Frisk in. The light's were already off, and his pupils seemed to glow gently in the darkness.

"goodnight, frisk," Sans said as he turned.

"Goodnight, Dad," Frisk said sleepily, and then gasped at their mistake as Sans halted. "Oh- I mean, Sans. I-I'm sorry, I didn't mean-" But when Sans turned, he had a soft smile on his face, and his sockets seemed to well with light blue tears as he leaned down to hug Frisk, pressing his teeth to their forehead in what they assumed was an imitation of a comforting kiss that Toriel often gave.

"it's fine," he said easily. "sleep tight, kid."

He slid the door shut quietly, and Frisk drifted to sleep with a happy smile.

\---

Toriel returned the next day around dinner time. Sans was dressed in the new clothes, sweat beading on his skull as he waited, fidgeting, in the living room. A delicious smell wafted from the kitchen; he had prepared dinner, or, rather, ordered from a fancy restaurant that delivered gourmet meals for a price, paid for by both himself and Frisk, completely depleting both of their personal savings. Frisk sat on the couch casually.

"Come on, Sans, don't look so _nerveous_ ," Frisk joked, but Sans barely managed a wider smile at the slight pun. "Seriously. It's _Mom._  Even if she...no, she _won't_ say no. Just relax a little before you sweat through your shirt." Sans gave a little chuckle, but he still didn't relax. He _was_ nervous, for the pure reason of this being Toriel. After all, the gentle monster was so kind, caring, everything about her resonating her goodness...

The door sounded her arrival before she was inside, and it startled Sans from his thoughts. He moved to stand near the door, but Frisk tugged on his wrist to argue, so he stayed put as Frisk went to the door. He could hear their voices.

"Mom!"

"Hello, my child." He was sure she hugged Frisk here. "Have you been good for Sans?"

"Mm-hm!" came the reply. "And he took good care of me, no bruises or scrapes or anything! We went to the mall yesterday and stuff, but mostly we stayed home and watched movies and stuff."

"That's good, Frisk. Speaking of, where is Sans? I need to thank him." Sans could feel his face flush a little blue at that, and he gave a soft chuckle at himself. He had eased onto the couch to lounge casually, as Frisk had been doing beforehand.

"Front room, I think. Can I bring Flowey outside?"

"Of course, but don't wander too far." Frisk's footsteps up the stairs were loud, and now, Toriel made her way into the living room.

"Ah, Sans, there you- oh, my." Sans had stood up at her entrance, and her eyes widened as she took in his appearance, words failing her.

"hey, tori," he said, somehow keeping his voice steady. "what's up?" Toriel blinked and recovered.

"Oh, nothing, I was just going to thank you for watching Frisk. And, I must say, you look...different." Sans felt his anxiety rise a little.

"yeah, the kid showed me some new clothes," he admitted. "what do you think?"

"Well...you certainly look handsome, Sans," she said earnestly, before she turned around quickly. "Ah, I think I will make some dinner-" As Frisk came downstairs with Flowey, they hurried past Toriel to speak to Sans urgently.

"Don't let her cook, okay? Take her to that Italian place, okay? You've got a reservation under your name. Sans Comic." They gave him a hug. "See ya,  _Dad_." They turned to Toriel. "Bye, Mom!" They hurried outside as Toriel chuckled.

"Ah, children. So, Sans, what would you like to-"

"can we- i mean, you and i- go out, actually?" Sans interrupted. Toriel glanced at him. "paps should be home soon, so he can watch frisk- you know how good he is with them and all." Toriel pondered for a moment before she smiled.

"I suppose we can," Toriel said finally. "I will tell Frisk."

\--

An hour later, Sans was telling the waitress - a short girl, no older than eighteen, who had clearly never seen a monster up close before but wasn't afraid - about the reservation. He was still dressed in his best clothes, and Toriel had changed into a nice dress that complimented her wide eyes. She was amazed; this place was surely expensive! Sans knew how the kid had afforded it, as well, having seen a large poster of Mettaton on the inside door of the place, assuming Frisk had spoken to the influential bot.

The two were seated at a small table and ordered their drinks, Toriel's being a glass of tea and Sans' being a glass of water. For a moment, it was quiet.

"so, uh...what do you think?" Toriel smiled.

"It's very nice here, but so expensive!" Sans shook his head.

"don't worry about that, it's all covered." Toriel nodded, as if already resolving to avoid the pricey menu items. "how was the weekend away?" Toriel sighed.

"It was not as easy as I had hoped," she admitted. "A teacher's conference, mostly because there were complaints about myself, and a few other monster teachers." Sans felt himself tense; someone complain about _Tori_? "But, in the end, we got everything settled. No harm done." Sans relaxed.

"well that's good," he commented.

"And how was Frisk?"

"pretty great. although, i gotta hand it to ya, tori, I don't know how you get the kid to bed at night." Toriel laughed.

"It _can_ be difficult, I know."

The dinner continued smoothly forward as the night progressed, until it was time to leave. Sans was grinning happily, and Toriel had her signature smile on, as well, her lips curving up gently in happiness. They were home quickly, and Sans held open the front door for her, causing her to chuckle, commenting, "Such a _gentle-Sans_ ," which made Sans laugh as well. The two slowly made their way upstairs to check on Frisk, and both were not surprised to see both Papyrus and Frisk sleeping deeply, both smiling. They made their way back down into the living room.

"Tonight was very nice, Sans," Toriel said. Sans smiled widely. "But..."

Oh, stars. But? But what? Sans didn't let his anxiety show, looking to Toriel curiously.

"I have to wonder if Frisk did not put you up to all this," she said, and Sans took notice that she seemed slightly nervous herself. He paused a moment.

"what do you mean?"

"Well, Frisk has told me that they see you and I as their Mom and Dad, and I wonder if they've been pushing you to make it seem as though...as though-"

"as though i like you? in that sense." Toriel nodded. Then Sans laughed.

"hah, no, tori, look," he said easily. "frisk didn't put me up to anything, other than planning for me. although, they did have a lot to do with this suit thing. not my style, but they said you'd like it, so..." Sans shrugged. "but no, i wouldn't have gone along with it if i didn't want to." For a moment, Toriel was quiet. Then she smiled.

"Well, to be honest, I liked you better before the suit," she said gently, to which Sans grinned.

"great. it was getting _hot_ ," he said, immediately taking the shirt off, showing he had his usual hoodie on somehow underneath, though the bulk hadn't shown before. Toriel laughed.

"You're funny, Sans."

"don't you mean _punny?_ "

"Perhaps." Suddenly, she leaned in and pressed her lips to his forehead. Sans smiled warmly at this. "It has been a long night, I think it is time to sleep." Sans nodded as they both headed upstairs to their respective rooms. "Goodnight, Sans."

"night, tori." He stayed in the hall until her door had shut, and as he walked past the kid's door, he said, "night paps, frisk. and for future reference, it's not polite to eavesdrop."

And he, too, went to bed.


End file.
